The stage of Mike Bartlett’s new play Bull (subtitled “The Bullfight Play”), included in the Brits Off-Broadway festival at 59E59 Theater, might mislead you into thinking you are at a boxing match rather than a bullfight. But that is just a geometric trompe l’oeil of Soutra Gilmour’s spare, industrial set design. Though the stage is square, like a boxing ring, tricked out with grey office carpet, a water cooler, and clear plastic file holders, the interaction between the players follows the tripartite form of a bullfight.